An Unusual Case of Cardiomegaly

A 64-year-old woman presented to the emergency department because of progressive fatigue and weight loss for the previous 3 months. She had a 10 pack-year history of smoking with no other significant medical history. Physical examination was unremarkable with normal cardiac and pulmonary auscultation. Her electrocardiogram showed sinus rhythm with very low voltages in all leads (Figure 1A). A chest x-ray film showed enlargement of the cardiac silhouette with normal pulmonary vascularization (Figure 1B). A transthoracic echocardiography was performed that revealed an homogeneous mass next to the right side of the heart without clear infiltration and moderate pericardial effusion (Figure 1C; see Movies I through III in the online-only Data Supplement). A contrast-enhanced full-body computed tomography showed a 12 × 8 cm soft-tissue density mass with some necrotic areas in the anterior and medium mediastinum (Figure 1D). No clear pericardial infiltration or involvement was noted, but small pleural and pericardial effusion was present. To better characterize the tumor, a cardiac magnetic resonance was performed, showing an 11 × 8.5 cm intrapericardial mass, with well-defined borders and no signs …